Starting Position: Place a 6-12" raised platform or box on the floor 3-6" in front of your feet on a non-slip surface. Stand with your feet hip-width apart or closer, arms by your sides. Pull your shoulder blades down and back. Engage your abdominal / core muscles to stabilize your spine.
Downward Phase: Shift your hips back and down. This will create a hinge-like movement at your knees. Continue to lower yourself until you feel your heels about to lift off the floor. Try to maintain a flat back by bending forward at the hips. Keep your head directly facing the box and position your arms where they offer the greatest degree of balance support.
Jumping Movement: With ONLY a very brief pause at the bottom of your downward phase, explode up through your lower body, fully extending your hips, knees and ankles. Swing your arms forward to help drive your vertical movement and land on top of the box. As you jump into the air, keep your feet level with each other and parallel with the floor.
Landing: The most important components of the landing phase are correct foot position and control of the forward movement in your knees. Excessive forward movement in the knees places additional stress on the joint.
Try to land softly and quietly on the mid-foot, rolling into the heels. Always push your hips back and down to absorb the impact of landing. Do not lock out your knees on your landing. Land with your trunk slightly forward, head aligned with your spine and back rigid or flat. Keep your abdominal / core muscles engaged, bracing your torso to protect your spine.
Exercise Variation: As you develop your jumping and landing skills, you can progress the exercise intensity and complexity by: (1) driving your arms behind you during the downward phase (illustrated), (2) driving your arms forward or upward (illustrated) during the jumping phase, (3) driving your knees towards your chest (illustrated) during the jumping phase., or (4) increasing the height of the raised platform or box.
Learn first how to squat and perform regular squat jumps before attempting to perform box jumps. The height of the platform / box should not exceed your vertical jump height.